Tungsten pentachloride is a precursor used in semiconductor processing for deposition of Tungsten containing films or etching processes. Tungsten (W) metal is used as plugs to connect M1 to copper interconnects of the FEOL and BEOL in logic and memory applications. See, e.g., US2009/0014879 to Park et al. Tungsten (W) or tungsten silicide (WSi2) may also serve as a metal gate deposited on Ti. See, e.g., US2014/0120723 to Fu et al. WCl5 has also been used to selectively etch substrates, such as metals, metal nitrides, and metal oxides. See, e.g., U.S. Pat. No. 9,449,843 to Korolik et al. and U.S. Pat. No. 9,595,466 to Fu et al.
Traven et al. disclose reactions of polysilanes and their Group IVB analogs with tungsten hexachloride. Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya (1975) 7, p. 1681.
Thorn-Csanyi et al. disclose reaction between WCl6 and olefins to show that the reduction of WCl6 with olefins is applicable to the preparation of WCl5. J. Molecular Catalysis, 1991, 65, 261-67.
WCl6 was reduced photolytically neat with tetrachloroethylene to produce hexachloroethane and WCl5. Inorganic Chemistry, 1968, 7, 6, 1227-1229.
A need remains for inexpensive and commercially viable synthesis methods to produce tungsten halides having purity suitable for use in the semiconductor industry.